Tuyere blocks for underfeed stokers



DeC 22, 1959 J. J. GRol-:NEMA

TUYERE BLOCKS Foa UNDERFEED sToKERs 2 Sheets-Sheet 1 Filed Dec. 14, 1956 Dec 22V, 1959 J. J. GROENEMA 2,918,025` y TUYERE BLOCKS FOR UNDERFEED STOKERS Filed Dec. 14, 1956 v 2 Sheets-Shea?l 2 J'il'illll" 15,'

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niteci. States Patent i.

TUYERE BLOCKS Fon UNDERFEED sToKERs Jan Jurjen 'Groenema, Hannover-Kleefeld, Germany Application December 14, 1956, Serial No. 628,454

Claims priority, application Netherlands Y December 16, 1955 1 '3 Claims. (Cl. 11G-44) This invention relates to improvements in tuyre blocks or blowing heads which are used for the casing of side tion between the outer surface of the blowing head and:

the surfaces surrounding its openings, but that the cooling effect of such a tuyre block or blowing headis determined by the proportion between the cooling surface and the furnace surface thereof. In other words, the

the combustion air, and that part of the outer surface which is turned towards the retort or the furnace bed controls the extent of cooling of the tuyre blocks.

In accordance with the instant invention, it is possible to .raise this fore-mentioned proportion between the cooling Surface and the furnace surface, which up to now was about 2 to 1 or 2.5 to l, by a novel design of the blowing head to a proportion of about to 1 or 11 to 1. Thus, my tuyre blocks or blowing heads share the advantages of grate rods for which, as is well known, the best proportions between cooling-surface and 4furnace surface are between about 12 to 1 and up to about 20 to 1.

An important object of the invention is to provide a tuyre-block or blowing head which is laminated in that it consists of two or more parts with slots therebetween, the blocks being situated at right angles to the direction of the underfeed and parallel to each other. The slots are enlarged to form relatively small openings which latter are regularly distributed over the blowing head and in the front Wall thereof to form rows parallel with the width of the block. The slots communicate with blowing-holes of multiple width in the region of the nonlaminated lower part of the front wall of the block.

A further object of the invention is to provide a composite blowing head of the above described character which is built up or made of separate laminae or segments.

Another object of the invention is to provide a blowing head which is assembled from grate-like profiled rods bedded into each other by means of adapted joints.

Among the advantages of the new form of the blowing head may be mentioned the very favorable proportion between cooling surface and furnace surface; and the high indeformability (deformation resistance) of the block. The air guidance and the cooling effect are much better than in blocks of known construction because the design of the blowing head obviates or mitigates especially heavy accumulations of solid material as well as considerable reductions of material in same locations. The material is distributed nearly evenly in proportion between the inner surface which is swept by all places so that the expansions due to heat or the' cooling is nearly uniformly distributed in the block in,

practically all directions.

A further advantage of the novel blocks is in' that'v theA heads of adjacent blowing blocks are situated side by side without touching each other; that means, also without cement or another binder. y

One form of the novel construction is illustrated by way of example in the accompanying drawings in which;

Figure 1 is a perspective view of three blowing heads constructed in accordance with my invention which are situated side by side adjacent to each other.

' Figure 2 is a perspective view of three segments of a single block, which segmentsv are shown in explodedv view.

Figure 3 is a perspective view of one segment.

' jIn the underfeed furnace, the fuel (e.g. coal) is fed in known manner by a screw (not shown) which works in a pipe, the fuel passing through an enlarged part of the pipe and being fed upwardly into the retort or furnace bed which is built of blowing head resting on the side wall 3 of the-enlarged part of the pipe. Collar 2 of the side wall 3 is received in grooves 1 of segments 7 of the blowing heads. These blowing heads (tuyre blocks) form, together with the corner blocks (not shown as they form no part of this invention) and the side walls 3, a right-angled retort or furnace bed. On theA outside, the tuyre blocks'are connected to a ring which z is built of horizontal plates 5 supported by the wall of' the tuyre box 6.

, yAs may be seen in Figs. 1 and 2, every tuyre block (blowing head) consists of a main lamina or segment 7 and of filler-laminae or segments 8 which are adjacent to and placed sidewise to the main segment. The segments 7 and 8 are formed with ribs 9 which extend from both major surfaces of the web of each segment adjacent to the latters meeting upper and front end facesl whichl extend from both major surfaces of the web of each segment adjacent to the latters upper and front end faces in such manner that, if the segments are asy sembled (see Fig. 1), the ribs 9 define air-channels 10 through which the combustion air is forced from the tuyre box 6 into the furnace bed. The term web, as utilized in this specification and in the appended claims, is intended to denote the upright plate-like main body portionsof segments 7, 8 from which the ribs 9 extend. As the air passes through the blocks, it cools selected zones of the latter which are heated to the highest temperatures during the combustion of the fuel (e.g. coal) in the furnace.

The front part of each main segment 7 is formed with two sets of substantially parallel ribs 11 which, together with similar ribs 11 of an adjacent and abutting main segment, define airl openings 12 through which additional combustion-air from the tuyre box 6 is blown into the retort. Ribs 11 as well as a pair of ribs 17 which latter do not extend fully to the front end face of a main segment are disposed at both sides or major surfaces of the web of each segment 7. These relatively long ribs 11 and 17 are adjacent to the lower zone of the front end face of the upright web of each main segment, while the relatively short ribs 9 extend from the web of each segment 7 adjacent to the latters upper end face and. the upper zone of its front end face.

The rear end of each main segment 7 is formed with a collar 13 which extends the full height thereof and. abuts against a similar collar of an adjacent main seg-- ment 7. Each collar 13 has an outer lug 14 which enters into a suitable recess in the adjacent plate 5. The lower end of collar 13 is provided with a rib 15 defining a. shoulder which supports the rear ends of webs of filler` segments 8. Each filler segment 8 has a nose portion:

Patented' ee. 2,2, (1959 is spaced from and above the uppermost rib 11 of the adjacent main segment 7. The nose portions of ller segments 8 fill out 'the space between two adjacent segrnents 7 above their. uppermost ribs 11 betweenthefjr'ontiend faces` of. segments 7 ,andl theol'ffset` ribsI 17.-

in that 'said' portions 16 extend dcrwvnwardly'over..nient-` bers17; The latter are received in cutouts 1 provided in the filler segments 8. Consequently, all 4filler segments 8,.t are secured inthe main planes o f their Webs, against movements under the influenceof heat. or distortim.v

As may be seen in Eig.Y 1, two filler-segments $V are provided-on earchfside ofV a main segment 7, but `it is,Y

equally Within the scope of my. invention to provide only onesegment 8 on each side ofy the Inain-segnjtent--=r '1l tov front,v and the collars 13 onthe rear of the segment 7 asthey will expandunder heat so that all segments in their working position have in heated condition the same width as the shaped parts. By. this simple means it is prevented that the upper part of the segments expands under heat more than theffront or rear parts.

Ther side or majorv surfaces of Vthe webs of segments 8` are .formed with ribs similar to ribs 9 on the major surfaces of the webs of main segments 7; thus., two adjacent segments 8 define therebetweenopenings similar to openings 10 formed between a mainf segment 7 and the abutting filler-,segment 8. Moreover, all segmentsl are provided with round bores 19 passing through the webs of s aid segments through which can be threaded -a rod 20' for firmly holding together the blocks.l i Y rIfhe ribs 9 on the webs of main segments 7 and laminae 8 'could be formed only on one side or major surface thereof.` The openings 10 in the head of eachblock, thatis, the openings between the respective upper vand front end faces of segments 7 and 8, also can be Alimited into vertical slots in accordance with a modification of the invention. v

The working temperatures of underfeed-stokers with tuyre blocks according to the invention areV at 4about 200 Cfand thus lower than with ordinaryV blowing heads. Theweight of the blowing head according Yto theinvention is about twice that of ordinary blowing heads. i y

Afterswitching off the air'in a furnace vwith known blowing heads the temperatures rise to between about 35.0 C. and about 530 C. i

Under the same circumstances, this temperature range is between about 200 C. and 300 C. if blowing heads according to the present invention are used.

What is claimed is:

1. A composite tuyre block for the side walls of underfeed stokers which comprises, in combination: a main segment having an upright web with a pair of major surfaces, an upper and a front end face, said'front end face having an upper Zone and a lower zone, short transverse ribs'extending from Ysaid'rnajor surfaces adjacent to the upper end face and to the upper zone of saidfront end face, and long transverse ribs extending from at least one major surfacein the proximity of'the lower zone of said front -endfacejat least one ller segment adjacent to each major surface from which said long ribs extend, each ller segment having an upright web with a pair of major surfaces, an upper and a front endface, a forward -endvand a rear end, and'ribs extending transversely from its major surfaces adjacent to` the upper end face and to the front end face thereof, the ribs of each ller segment abutting the short ribs of the main segment and defining air channels therebetween, the upper end face and the upper zone of the front end faceofl said main segment being aligned withH the upper end face and the front endface, respectively, of each flller segment, and the long ribs of said main segrnent extending beneath and supporting the forward end of each filler segment; and means forming part of said main segment for supporting the rear end of each ller segment.

2. A tuyre block as set forth in claim 1, wherein the means for supporting the rear end of each filler segmentl comprises a coll-ar extending transversely from the web. of said main segment and having a shoulder extending. beneath the rear end of each filler segment.

3. A tuyre block as set forth in claim 2, wherein the uppermost long ribs on which the forward end of` each filler segment is supported are offset from the front end face of said main segment and each filler segment" has a nose portion extending downwardly over said offset long ribs.

References Citerdin the file of this patent UNITED STATES PATENTS 2,449,602 Hall Sept. 21, 19.48

FOREIGN PATENTS 634,810 Germany Aug. .13, 1936 

